Sub mergeFiles3()
Dim mainWorkbook, myPath, rngLr, Destn As Range, fname
myPath = "C:\Users\Public\Documents\" 'adjust
Set mainWorkbook = Application.ActiveWorkbook
With mainWorkbook.Sheets(1)
'.Activate
Set rngLr = .Cells.Find("*", searchorder:=xlByRows, searchdirection:=xlPrevious)
If rngLr Is Nothing Then 'then it's an empty sheet.
Set Destn = .Cells(3, 3)
Else
Set Destn = .Cells(Application.Max(rngLr.Row + 1, 3), 3)
End If
End With
fname = Dir(myPath & "*.xlsx")
Do While fname <> ""
With Workbooks.Open(myPath & fname)
.Worksheets(1).UsedRange.Rows(1).Copy Destn
.Close False
End With
Set Destn = Destn.Offset(1)
fname = Dir()
Loop
End Sub